Biological Phosphorus Removal Activated Sludge Process in Warm Climates CaoYe Shi Publishing London* New York
Contents Preface Acknowledgements About the author Nomenclature ix xi xiii xv Chapter 1 General introduction 1 1.1 Wastewater treatment in warm climates 1 1.2 Biological nitrogen removal in warm climates 2 1.3 Enhanced biological phosphorus removal (EBPR) in warm climates 2 1.4 Focus areas of the book...3 1.5 Approaches: between up- and down-streams 3 1.6 Structure of the book 3 Chapter 2 Introduction: biological phosphorus removal activated sludge process of municipal wastewater treatment in warm climates 5 2.1 Biological nitrogen removal in warm climates 5 2.2 Enhanced biological phosphorus removal: PAO and GAO 6 2.2.1 Metabolisms of PAO and GAO 6 2.2.2 Temperature and sludge retention time 9 2011 IWA Publishing. Biological Phosphorus Removal Activated Sludge Process in Warm Climates. By Cao Ye Shi. ISBN: 9781843393818. Published by IWA Publishing, London, UK.
vi Biological Phosphorus Removal Activated Sludge Process in Warm Climates 2.2.3 ph 9 2.2.4 Types of substrates and COD/P ratio 10 2.2.5 Modelling 10 2.2.6 Identification of PAO and GAO 11 2.3 An unanswered question: Whether EBPR works in warm climates under practical site conditions? 11 2.4 Objectives and the research programme 12 2.4.1 Objectives 12 2.4.2 Research programme 12 Chapter 3 Enhanced biological phosphorus removal in a full-scale AIO activated sludge process at 30 C 15 3.1 Introduction 15 3.2 Materials and methods 16 3.2.1 Site conditions 16 3.2.2 Sampling and analysis 16 3.3 Results and discussion 17 3.3.1 Hydraulic flow and characterization of conventional parameters and SCFAs of primary effluent 17 3.3.2 Performance of Enhanced Biological Phosphorus Removal (EBPR) 18 3.3.3 Fates of the SCFAs 22 3.3.4 Phosphate Accumulating Organism (PAO) development 24 3.3.5 SVI and sludge morphology changes 24 3.4 Conclusions 26 Chapter 4 Enhanced biological phosphorus removal during the retrofitting from an anoxic to an anaerobic selector in a full-scale activated sludge process at 30 C 29 4.1 Introduction 29 4.2 Materials and methods 30 4.2.1 Activated sludge unit 30 4.2.2 Sampling and analysis 31 4.2.3 Sequencing batch reactor experiment 31 4.3 Results and discussion 31 4.3.1 Characterisation of the primary effluent 31 4.3.2 Performance development of the activated sludge process 32 4.3.3 Enhanced Biological Phosphorus Removal (EBPR) 34 4.3.4 Mechanism(s) of the Enhanced Biological Phosphorus Removal 37 4.4 Conclusions 39
Contents vii Chapter 5 Process performance and competition between PAO and GAO in the enhanced biological phosphorus removal activated sludge process of the municipal sewage treatment at 30 C, 20 C and 15 C 41 5.1 Introduction 41 5.2 Materials and methods 43 5.2.1 Laboratory system and process 43 5.2.2 Sampling program and analysis 45 5.2.3 FISH and chemical staining 45 5.2.4 Phosphorus release and uptake batch test 46 5.3 Results 47 5.3.1 Characterisation of primary effluent 47 5.3.2 Performance of the process 48 5.3.3 Process analysis and microbial community study 52 5.4 Discussion 75 5.4.1 Effects of additional COD (HAc) 75 5.4.2 Effects of ph control 76 5.4.3 Anoxic and aerobic P uptake 76 5.4.4 Microbial community: PAO and GAO 77 5.4.5 Different mechanisms of EBPR 78 5.4.6 Effects of temperature 78 5.4.7 Interrelationships between temperature, carbon, ph, microbial community and performance 80 5.4.8 Denitrification, P uptake and release in the FST 80 5.4.9 EBPR in warm climates 81 5.4.10 Operational strategy of the EBPR activated sludge process to cope with seasonal temperature changes 82 5.5 Conclusions 83 Chapter 6 Pilot investigation of the EBPR of industrial wastewater treatment with an integrated UASB, activated sludge-membrane process at 30 C 87 6.1 Introduction 87 6.2 Materials and methods 88 6.2.1 Pilot system and process configurations 88 6.2.2 Sampling program and analysis 90 6.3 Results and discusions 91 6.3.1 Wastewater characterisation 91 6.3.2 Performance of the UASB reactor 92 6.3.3 Performance of the MBR process 93 6.3.4 Process analysis of EBPR 96 6.3.5 Microbial community study 106
viii Biological Phosphorus Removal Activated Sludge Process in Warm Climates 6.3.6 Cleaning of the MBRand RO membranes 108 6.3.7 Effluent quality and feasibility of reuse 108 6.4 Conclusions 110 Chapter 7 Summary and outlook 113 7.1 Experimental conditions 113 7.1.1 Sewage in warm climates 113 7.1.2 Process configuration 114 7.2 Major findings 114 7.2.1 Fate of HAc and HPr 114 7.2.2 Effects of additional HAc 114 7.2.3 Anoxic and aerobic P uptake 115 7.2.4 Mechanisms of the EBPR 115 7.2.5 Microbial community: PAO and GAO 115 7.2.6 Effect of temperature 116 7.2.7 Interrelationships between temperature, carbon substrate, ph, microbial community and performance 116 7.2.8 Recommendations for the practical applications of EBPR of municipal sewage treatment in warm climates 117 7.2.9 EBPR of industrial wastewater treatment in warm climates 118 7.3 Outlook 118 7.3.1 Microbiology study 118 7.3.2 Process investigation 119 7.3.3 Modelling 120 7.3.4 Long term perspective on nutrient removal 120 References 121 Index 127